FIG. 1 illustrates a packer in a run in position akin to a Premier® model offered by Baker Hughes Incorporated of Houston, Tex. The seal element assembly 17, 18, 19 and 20 is surrounded by backup rings 15. A lower gage ring 21 holds a lock ring 22 so that the set position can be held. Slips 11 after breaking shear pin 12 mounted through a bore 13 moves axially and up the ramp of cone 14 to engage the surrounding tubular after the sealing element assembly 17, 18, 19 and 20 is axially compressed against the surrounding tubular. These parts are mounted to the outer surface of mandrel 10. To prevent extrusion between the mandrel 10 and the backup ring 15 is a wedge ring 16 that is pushed into a corner against the backup ring 15 and the mandrel 10. This ring is usually made from PEEK and is expensive to produce and very difficult to insert. Beyond that it can move during a set and become ineffective for its intended purpose if it is displaced from its original location during the set. It can be pushed out of the corner where it was inserted, roll on its axis, or simply not fully installed into the intended corner location to control axial extrusion along the mandrel.
The present invention seeks to overcome these problems by integrating an abutting ring to the extrusion barrier adjacent the mandrel to employ the forces developed in the sealing element to press the abutting ring firmly against a mandrel to close an extrusion gap there. One side of the ring is preferably an extension of the inside dimension of the base ring for the backup ring while the sealing element fills a gap between a tapered opposite side of the abutting ring and the backup ring structure. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.